Piezoelectric actuator device

Abstract

The present invention relates to a piezoelectric actuator device that enables hysteresis of the amount of displacement in the piezoelectric actuator to be reduced, enables the system configuration to be simplified, and for which a high voltage need not be applied. A first circuit 1 comprises a piezoelectric actuator element 11 and a first resistor circuit 12, and the piezoelectric actuator element 11 and first resistor circuit 12 are connected in parallel. A second circuit 2 comprises a capacitor circuit 21 and a second resistor circuit 22, and the capacitor circuit 21 and second resistor circuit 22 are connected in parallel. The first circuit 1 and second circuit 2 are connected in series to form a series circuit, and both ends of that series circuit are led to a pair of input terminals T 1 and T 2.

1. A piezoelectric actuator device comprising a first circuit and a second circuit, wherein;
 said first circuit comprises a piezoelectric actuator element and a first resistor circuit, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; and 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals, wherein said piezoelectric actuator element comprises a mechanical output device configured to drive a component. 
 
   
   
     2. A piezoelectric actuator device comprising a first circuit and a second circuit, wherein:
 said first circuit comprises a piezoelectric actuator element and a first resistor circuit, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals; and 
 when the capacitance of said piezoelectric actuator element is represented by Ca, the resistance of said first resistor circuit is represented by R 1 , the capacitance of said capacitor circuit is represented by C 1 , and the resistance of said second resistor circuit is represented by R 2 , 
 said piezoelectric actuator device satisfies the following conditional expression:
     Ca·R   1 < C   1 · R   2 . 
 
 
   
   
     3. The piezoelectric actuator device according to  claim 1 , wherein;
 said piezoelectric actuator device further comprises a rectifying circuit; and 
 said rectifying circuit is connected in parallel to said piezoelectric actuator element and is oriented in the opposite direction with respect to the polarity of the voltage to be applied to said piezoelectric actuator element. 
 
   
   
     4. The piezoelectric actuator device according to  claim 2 , wherein;
 said piezoelectric actuator device further comprises a rectifying circuit; and 
 said rectifying circuit is connected in parallel to said piezoelectric actuator element and is oriented in the opposite direction with respect to the polarity of the voltage to be applied to said piezoelectric actuator element. 
 
   
   
     5. A piezoelectric actuator circuit comprising a first circuit and a second circuit, wherein;
 said first circuit comprises a piezoelectric actuator element and a first resistor circuit, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; and 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals, wherein said piezoelectric actuator element comprises a mechanical output device configured to drive a component. 
 
   
   
     6. A piezoelectric actuator circuit comprising a first circuit and a second circuit, wherein:
 said first circuit comprises a piezoelectric actuator element and a first resistor circuit, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals; and 
 when the capacitance of said piezoelectric actuator element is represented by Ca, the resistance of said first resistor circuit is represented by R 1 , the capacitance of said capacitor circuit is represented by C 1 , and the resistance of said second resistor circuit is represented by R 2 , 
 said piezoelectric actuator circuit satisfies the following conditional expression:
     Ca·R   1 < C   1 · R   2 . 
 
 
   
   
     7. The piezoelectric actuator circuit according to  claim 5 , wherein;
 said piezoelectric actuator circuit further comprises a rectifying circuit; and 
 said rectifying circuit is connected in parallel to said piezoelectric actuator element and is oriented in the opposite direction with respect to the polarity of the voltage to be applied to said piezoelectric actuator element. 
 
   
   
     8. The piezoelectric actuator circuit according to  claim 6 , wherein;
 said piezoelectric actuator circuit further comprises a rectifying circuit; and 
 said rectifying circuit is connected in parallel to said piezoelectric actuator element and is oriented in the opposite direction with respect to the polarity of the voltage to be applied to said piezoelectric actuator element. 
 
   
   
     9. A piezoelectric actuator device comprising a first circuit and a second circuit, wherein:
 said first circuit comprises a piezoelectric actuator element and a first resistor circuit, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals; and 
 the impedance of the first circuit and the impedance of the second circuit satisfies the expression:
   | Z   1 |>| Z   2 |. 
 
 
   
   
     10. A piezoelectric actuator circuit comprising a first circuit and a second circuit, wherein:
 said first circuit comprises a piezoelectric actuator element and a first resistor circuit, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; and 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals; and 
 the impedance of the first circuit and the impedance of the second circuit satisfies the expression:
   | Z   1 |>| Z   2 |. 
 
 
   
   
     11. A piezoelectric actuator device comprising a first circuit and a second circuit, wherein;
 said first circuit comprises a first resistor circuit and a piezoelectric actuator element for converting an input voltage into an output mechanical displacement, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals; and 
 said piezoelectric actuator element comprises a mechanical output device configured to drive a component. 
 
   
   
     12. A piezoelectric actuator device comprising a first circuit and a second circuit, wherein:
 said first circuit comprises a first resistor circuit and a piezoelectric actuator element for converting an input voltage into an output mechanical displacement, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals; and 
 when the capacitance of said piezoelectric actuator element is represented by Ca, the resistance of said first resistor circuit is represented by R 1 , the capacitance of said capacitor circuit is represented by C 1 , and the resistance of said second resistor circuit is represented by R 2 , 
 said piezoelectric actuator device satisfies the following conditional expression:
     Ca·R   1 < C   1 · R   2 . 
 
 
   
   
     13. A piezoelectric actuator circuit comprising a first circuit and a second circuit, wherein;
 said first circuit comprises a first resistor circuit and a piezoelectric actuator element for converting an input voltage into an output mechanical displacement, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals; and 
 said piezoelectric actuator element comprises a mechanical output device configured to drive a component. 
 
   
   
     14. A piezoelectric actuator circuit comprising a first circuit and a second circuit, wherein;
 said first circuit comprises a first resistor circuit and a piezoelectric actuator element for converting an input voltage into an output mechanical displacement, said piezoelectric actuator element and said first resistor circuit being connected in parallel; 
 said second circuit comprises a capacitor circuit and a second resistor circuit, said capacitor circuit and said second resistor circuit being connected in parallel; 
 said first circuit and said second circuit are connected in series to form a series circuit, both ends of that series circuit being led to a pair of input terminals; and 
 when the capacitance of said piezoelectric actuator element is represented by Ca, the resistance of said first resistor circuit is represented by R 1 , the capacitance of said capacitor circuit is represented by C 1 , and the resistance of said second resistor circuit is represented by R 2 , 
 said piezoelectric actuator circuit satisfies the following conditional expression:
     Ca·R   1 < C   1 · R   2 .